The National Development and Reform Commission (NDRC) estimates the bulbs will help save 6.2 billion kWh of electricity and cut carbon dioxide emissions by 6.2 million tons and sulfur dioxide by 62,000 tons in a year.

Statistics from the China Electricity Council and the Ministry of Industry and Information Technology show that last year China consumed 3.42 trillion kWh of electricity and produced at least 1.1 million tons of sulfur dioxide in 2008. The figure for carbon dioxide exceeded 5 billion tons in 2007.

Like Zhang Youfang, many people bought more than the five bulbs covered by the preferential policy.

Zhang Guitian, 80, said he planned to use them in all the lights in his house and use environment-friendly paint to decorate his home this month.

"Emissions reduction and energy saving should really start from us ordinary people," he said.